X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;ds=sidebyside;f=virt-df%2Fvirt_df_lvm2.ml;h=afcab662dbf9e6e3b171687c50776723b0361beb;hb=b25ac692bd7107b56850de8fa25123791dfdf73e;hp=8dc0c05f9bc22fd92e16ec6b07ef95cb5f762abf;hpb=9bb5f67c0d8a6e8dad7de72e2488ee73c90f7d43;p=virt-top.git

diff --git a/virt-df/virt_df_lvm2.ml b/virt-df/virt_df_lvm2.ml
index 8dc0c05..afcab66 100644
--- a/virt-df/virt_df_lvm2.ml
+++ b/virt-df/virt_df_lvm2.ml
@@ -21,18 +21,89 @@
 *)
 
 open Printf
+open Virt_df_gettext.Gettext
+open Virt_df
 
-(* Int64 operators for convenience. *)
-let (+^) = Int64.add
-let (-^) = Int64.sub
-let ( *^ ) = Int64.mul
-let (/^) = Int64.div
+let plugin_name = "LVM2"
 
-let probe_lvm2 target part_type fd start size =
-  Virt_df.ProbeFailed "LVM2 not supported yet"
+let sector_size = 512
+let sector_size64 = 512L
+
+(* Probe to see if it's an LVM2 PV.  Look for the "LABELONE" label. *)
+let rec probe_pv lvm_plugin_id dev =
+  try
+    let uuid, _ = read_pv_label dev in
+    if debug then
+      eprintf "LVM2 detected PV UUID %s\n%!" uuid;
+    { lvm_plugin_id = lvm_plugin_id; pv_uuid = uuid }
+  with exn ->
+    if debug then prerr_endline (Printexc.to_string exn);
+    raise Not_found
+
+and read_pv_label dev =
+  (* Load the first 8 sectors.  I found by experimentation that
+   * the second sector contains the header ("LABELONE" etc) and
+   * the nineth sector contains some additional information about
+   * the location of the current metadata.
+   *)
+  let bits = dev#read_bitstring 0L (9 * sector_size) in
+
+  (*Bitmatch.hexdump_bitstring stdout bits;*)
+
+  bitmatch bits with
+  | sector0 : sector_size*8 : bitstring; (* sector 0 *)
+    labelone : 8*8 : bitstring;		(* "LABELONE" *)
+    padding : 16*8 : bitstring;		(* Seems to contain something. *)
+    lvm2_ver : 8*8 : bitstring;		(* "LVM2 001" *)
+    uuid : 32*8 : bitstring;		(* UUID *)
+    padding2 : (sector_size-64)*8 : bitstring; (* to end of second sector *)
+    sector234567 : sector_size*8 * 6 : bitstring; (* sectors 2-6 *)
+    padding3 : 0x28*8 : bitstring;      (* start of sector 8 *)
+    metadata_offset : 32 : littleendian;(* metadata offset *)
+    padding4 : 4*8 : bitstring;
+    metadata_length : 32 : littleendian	(* length of metadata (bytes) *)
+      when Bitmatch.string_of_bitstring labelone = "LABELONE" &&
+	   Bitmatch.string_of_bitstring lvm2_ver = "LVM2 001" ->
+    let metadata_offset = metadata_offset +* 0x1000_l in
+    let metadata = read_metadata dev metadata_offset metadata_length in
+    (*prerr_endline metadata;*)
+    let uuid = Bitmatch.string_of_bitstring uuid in
+
+    uuid, metadata
+
+  | _ ->
+    invalid_arg
+      (sprintf "LVM2: read_pv_label: %s: not an LVM2 physical volume" dev#name)
+
+and read_metadata dev offset32 len32 =
+  if debug then
+    eprintf "metadata: offset 0x%lx len %ld bytes\n" offset32 len32;
+
+  (* Check the offset and length are sensible. *)
+  let offset64 =
+    if offset32 <= Int32.max_int then Int64.of_int32 offset32
+    else invalid_arg "LVM2: read_metadata: metadata offset too large" in
+  let len64 =
+    if len32 <= 2_147_483_647_l then Int64.of_int32 len32
+    else invalid_arg "LVM2: read_metadata: metadata length too large" in
+
+  if offset64 <= 0x1200L || offset64 >= dev#size
+    || len64 <= 0L || offset64 +^ len64 >= dev#size then
+      invalid_arg "LVM2: read_metadata: bad metadata offset or length";
+
+  (* If it is outside the disk boundaries, this will throw an exception,
+   * otherwise it will read and return the metadata string.
+   *)
+  dev#read offset64 (Int64.to_int len64)
+
+(* We are passed a list of devices which we previously identified
+ * as PVs belonging to us.  From these produce a list of all LVs
+ * (as devices) and return them.  Note that we don't try to detect
+ * what is on these LVs - that will be done in the main code.
+ *)
+let list_lvs devs =
+  []
 
 (* Register with main code. *)
 let () =
-  Virt_df.fs_register
-    [ 0x8e ]				(* Partition type. *)
-    probe_lvm2
+  lvm_type_register plugin_name probe_pv list_lvs